London, August 10
A suspected Al-Qaida plot with strong Pakistani connection to blow up as many as 10 civilian airliners during flights from the UK to the US was foiled today with the arrest of 24 persons in the UK and seven persons in Karachi.

Pakistan Foreign Office Spokeswoman Tasneem Aslam said from Islamabad, “Arrests have been made after exchange of information between the two governments” of Britain and Pakistan.

She said Pakistan intelligence agencies had tipped off their British counterparts that resulted in averting the disaster. The plot, that triggered a worldwide security alert and chaos at airports, envisaged using explosives smuggled into the planes in handbags.

The arrested persons are believed to be British citizens with many of Pakistani origin.

The US said the plan was “suggestive” of an Al- Qaida plot and issued its highest terror alert ever for commercial flights from Britain besides banning all liquids and gels from aircraft.

Security officials here suspected that some liquid explosives could be mixed during the flights into a lethal concoction. They said the terrorists had planned simultaneous attacks on US-bound aircraft.

The plot was “very significant” and was designed to “bring down a number of aircraft through mid-flight explosions causing a considerable loss of life”, British Home Secretary John Reid said.

“It amounted to a major threat to the UK and international partners” and the police were confident that the main players had been accounted for, he said.

Mr Reid said the scale of the terror plot was potentially bigger than the September 11 attacks in the US. “Had this plot been carried out, the loss of life to innocent civilians would have been on an unprecedented scale.”

British Intelligence agency M15 said the current threat level is critical — the highest possible—meaning thereby “an attack is expected and indicates an extremely high level of threat to the UK”.

“The plot was intended to be mass murder of unimaginable scale,” Metropolitan Police Deputy Commissioner Paul Stephenson said, adding that “we believe that the terrorist aim was to smuggle explosives onto aeroplanes in hand baggage and to detonate these inflight.

“This is about people who are desperate.... who want to do things that no right minded citizen of this country or any other country would want to tolerate,” Mr Stephenson said.

In the US, the Department of Homeland Security (DHS) raised the terror threat to the highest level of “severe” or red for commercial flights originating in the UK and bound for the US. It also prohibited any liquids, including any beverages, hair gels and lotions, from being carried on aircraft.

A spokesman said passengers were advised that no electrical or battery-powered items, including laptops, mobile phones, iPods and remote controls, could be carried in the cabin and must be checked in as hold baggage.